A strict alcohol ban is in force, and anyone caught breaking the rules gets an on-the-spot fine.

This year for the first time, the party area was fenced off for an organised alcohol-free event.

The crowds still kept emergency services busy, and at least two underage drinkers were taken away by ambulance.

Police wouldn't reveal numbers, but say most people were well-behaved.

"Most of the crowd is here to have a good time and it's really great," says Inspector John Kelly, Eastern Waikato Area Commander.

"Enforcement of the liquor ban has brought a positive change in the people who turn up. When everyone's gone home tonight, we'll look around and there'll be hardly any bottles on the road, which is a positive sign for us."